Hundreds of variants have been observed in several PD genes that showed a clear association, including α-synuclein (SNCA, PARK4), parkin (PARK2), UCH-L1 (PARK5), PINK1 (PARK6), DJ-1 (PARK7), LRRK2 (PARK8), ATP13A2 (PARK9), GBA, VPS35 (PARK17), EIF4G1, and PARK1610,11. This evidence concerns the gene SNCA and Parkinson disease.